﻿
using System.IO;
using System.Net;

namespace LBSoft.Common.DotNetFile
{
    public class ImgDownloadHelper
    {
        /// <summary>
        /// 下载图片
        /// </summary>
        /// <param name="picUrl">图片Http地址</param>
        /// <param name="savePath">保存路径</param>
        /// <param name="timeOut">Request最大请求时间，如果为-1则无限制</param>
        /// <returns></returns>
        public static bool DownloadPicture(string picUrl, string savePath, int timeOut)
        {
            bool value = false;
            WebResponse response = null;
            Stream stream = null;
            try
            {
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(picUrl);
                if (timeOut != -1) request.Timeout = timeOut;
                response = request.GetResponse();
                stream = response.GetResponseStream();
                if (!response.ContentType.ToLower().StartsWith("text/"))
                    value = SaveBinaryFile(response, savePath);
            }
            finally
            {
                if (stream != null) stream.Close();
                if (response != null) response.Close();
            }
            return value;
        }
        private static bool SaveBinaryFile(WebResponse response, string savePath)
        {
            bool value = false;
            byte[] buffer = new byte[1024];
            Stream outStream = null;
            Stream inStream = null;
            try
            {
                if (File.Exists(savePath)) File.Delete(savePath);
                outStream = System.IO.File.Create(savePath);
                inStream = response.GetResponseStream();
                int l;
                do
                {
                    l = inStream.Read(buffer, 0, buffer.Length);
                    if (l > 0) outStream.Write(buffer, 0, l);
                } while (l > 0);
                value = true;
            }
            finally
            {
                if (outStream != null) outStream.Close();
                if (inStream != null) inStream.Close();
            }
            return value;
        }

        /// <summary>
        /// 下载图片
        /// </summary>
        /// <param name="url"></param>
        /// <param name="pat"></param>
        public static void DownloadImage(string url, string path)
        {
            WebRequest request = WebRequest.Create(url);
            request.ContentType = "image/jpg";
            WebResponse response = request.GetResponse();
            using (Stream reader = response.GetResponseStream())
            {
                using (FileStream writer = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write))
                {
                    byte[] buffer = new byte[512];
                    int c = 0;
                    while ((c = reader.Read(buffer, 0, buffer.Length)) > 0)
                    {
                        writer.Write(buffer, 0, c);
                    }
                }
            }
        }
    }
}
